body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 20px;
  background: linear-gradient(0.25turn, #3f87a6, #ebf8e1, #f69d3c);  color: #333;
  text-align: center;
   min-height: 100vh;
  font-family: 'Segoe UI', Arial, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
}

h1 {
  color: #004aad;
}

#status {
  margin-bottom: 20px;
  font-weight: bold;
  color: green;
}

.tables {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 30px;
}

.table-container {
  background: white;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
  width: 300px;
  max-height: 600px;
  overflow-y: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 10px;
  border-bottom: 1px solid #ddd;
}

th {
  background-color: #e6f0ff;
  font-weight: bold;
}

td {
  font-size: 16px;
}

tbody tr:last-child td {
  border-bottom: none;
}
.card {
  transition: transform 0.17s cubic-bezier(.4,1.8,.6,1), box-shadow 0.17s;
  will-change: transform;
  perspective: 900px;
}

button {
  display: inline-block;
  margin: 14px 10px 0 0;
  padding: 12px 22px;
  font-size: 1.07rem;
  border-radius: 9px;
  border: none;
  outline: none;
  font-family: inherit;
  font-weight: 600;
  background: linear-gradient(95deg, #e2eafc 0%, #cde3f8 70%);
  color: #1b2b49;
  box-shadow: 0 2px 10px rgba(44,55,80,0.07);
  cursor: pointer;
  transition: background 0.19s, box-shadow 0.19s, color 0.19s;
}

button:hover, button:focus {
  background: linear-gradient(95deg, #dbeafe 0%, #bee3f8 100%);
  color: #0a1743;
  box-shadow: 0 4px 18px rgba(44,55,80,0.13);
}

#undoBtn, #resetBtn {
  background: linear-gradient(95deg, #fff3cd 0%, #fde68a 80%);
  color: #7a511b;
  margin-right: 12px;
}

#undoBtn:hover, #undoBtn:focus,
#resetBtn:hover, #resetBtn:focus {
  background: linear-gradient(95deg, #fff9db 0%, #fef08a 90%);
  color: #573602;
}

button svg {
  vertical-align: middle;
  margin-right: 7px;
  font-size: 1.1em;
}
.main-nav {
  width: 100%;
  max-width: 900px;
  margin: 0 auto 28px auto;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 32px;
  background: none;
  padding: 32px 0 8px 0;
  font-family: inherit;
}
.nav-link {
  color: #2563eb;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.5em;
  transition: color 0.15s, border-bottom 0.14s;
  border-bottom: 2.5px solid transparent;
  padding-bottom: 1px;
}
.nav-link:hover, .nav-link.active {
  color: #185adf;
  border-bottom: 2.5px solid #2563eb;
  text-decoration: none;
}

.main-nav {
  width: 100%;
  max-width: 900px;
  margin: 0 auto 28px auto;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 64px;       /* Increased gap between links */
  background: none;
  padding: 32px 0 8px 0;
  font-family: inherit;
}
  .about-card {
      margin: 54px auto 0 auto;
      max-width: 590px;
      background: #fff;
      border-radius: 18px;
      box-shadow: 0 6px 28px #d5d5d58c;
      padding: 36px 32px 30px 32px;
      text-align: center;
    }

      .about-card a {
      color: #2563eb;
      text-decoration: underline;
      word-break: break-all;
    }
    .back-link {
      display: inline-block;
      margin: 38px 0 0 0;
      font-size: 1.05em;
      color: #222;
      text-decoration: none;
      background: #e8eefa;
      padding: 10px 22px;
      border-radius: 10px;
      transition: background .18s;
    }
    .back-link:hover {
      background: #dde6f8;
      color: #165be2;
    }
    @media (max-width: 650px) {
      .about-card { padding: 20px 3vw 16px 3vw; max-width: 99vw;}
    }